- Consolidation therapy: Patients receive radioimmunotherapy comprising rituximab IV over 3-4 hours followed by indium In 111 ibritumomab tiuxetan (for radioimaging) IV over 10 minutes on day 1. Patients then undergo imaging on days 1 and 2. If biodistribution is acceptable, patients receive rituximab IV over 3-4 hours followed by yttrium Y 90 ibritumomab tiuxetan IV over 10 minutes on day 8.